Importance: While programs addressing youth violence have multiplied and have been subjected to increased empirical evaluation, less has been done to evaluate primary prevention of sexual violence, particularly in the high risk environment of college campuses. Prevention science has demonstrated that prevention messages must begin at an early age and need to be reiterated throughout secondary and post-secondary education. This is especially true for sexual violence, which peaks during the college years. Objective: To extend and evaluate promising preliminary work on preventing sexual violence by using a pro-social bystander approach (Research objective 1B in the current RFA), training and empowering first year college students to actively intervene before, during, and after the occurrence of risky situations in order to ultimately reduce relationship violence. We hypothesize that participants receiving the intervention will consequently manifest reduced acceptance of rape myths, reduction in norms supporting dating violence, increased bystander efficacy, and increased bystander behaviors as well as lower assault proclivity and lower victimization. These gains will be in comparison to a control group which does not receive the program and has lesser exposure to social marketing messages Study Design: The proposed study will use a multi-method approach, a technique strongly recommended in the prevention science literature. It builds on earlier work by this research team which has conducted the first experimental evaluation of a comprehensive bystander program and community-wide bystander-oriented social marketing campaign. We will empirically evaluate the efficacy of two forms of primary prevention: 1) a multi-session, in-person prevention program, and 2) a bystander-oriented social marketing campaign. The research will examine both the independent and combined effects of each preventative strategy. Participants: Seven hundred participants across two college campuses will be used to evaluate the in-person program. They will be recruited from the pool of first year students on each campus and will be randomly assigned to either the prevention or control groups, and will be followed longitudinally for up to 12 months. Settings: Participants will be drawn from two very different college campuses (one campus that is primarily a rural residential campus and another which is a more urban, diverse, commuter school). On both campuses there will be specific focus on the high risk groups of first year college students. Both university communities will be exposed to the bystander-oriented social marketing campaign. Ten percent of each campus will answer questions on their exposure to the social marketing campaign and its impact on their attitudes and behaviors. Interventions: Two methods of prevention will be assessed individually and together in the proposed study. One is a multi-session, in-person educational program that uses active learning strategies and best practices from theory and research on prevention (including the Health Belief Model and founding work on bystander prevention) to teach participants how to be empowered bystanders before, during, or after instances of relationship violence (particularly sexual assault). The second method of prevention, the bystander-oriented social marketing campaign will consist of a multi-method campaign portraying bystander behavior. The "tag line" for the social marketing campaign is "know your power, step in, speak up, you can make a difference." The research team will "blanket" each university with three types of mixed media for 30 days during the first and second year of the proposed research. The first component of the mixed bystander-oriented social marketing campaign is a series of four posters portraying "typical" college scenes explicitly modeling bystander behavior in the prevention of violence against women. The second component of the social marketing campaign consists of "tail-wrapping" eight campus-based shuttle buses with life-size posters of the four social marketing campaign posters. The third campaign component will include products displaying the social marketing campaign tag line, "know your power, step in, speak up, you can make a difference." The marketing products will be distributed to all first year students. It is an important feature of our bystander prevention program model that certain aspects of the program and social marketing campaign are specific to the community in which they are implemented (e.g., students modeling in the posters, examples of incidents of sexual and relationship violence discussed in the in-person program). Outcomes: Outcome measures draw from best practices in sexual violence and dating violence prevention to date, including specific measures of bystander attitudes, efficacy, decisional processes, and actual social behaviors. Measures also include peer norms, rape myth acceptance, and measures of behavioral intent to commit sexual assault and a measure of victimization. The research team believes that effective community based prevention that finds roles for all community members to play in reducing sexual and relationship violence is a key component of primary prevention efforts. The proposed research will enable us to replicate our work in this area on a larger scale in two very different communities serving college-age individuals.